To replace relic, snoop in cemetery (10)
I believe the answer is:
necropolis
'cemetery' is the definition.
(synonyms)
'to replace relic snoop' is the wordplay.
'to replace' indicates an anagram (I've seen 'replacing' mean this (placing again)).
'relic'+'snoop'='relicsnoop'
'relicsnoop' with letters rearranged gives 'NECROPOLIS'.
'in' acts as a link.
(Other definitions for necropolis that I've seen before include "Ripon Close (anag) - cemetery" , "Large ancient cemetery" , "burial site" .)